Our little one is going to turn 4 years old and what better way to take him for the first time to the great amusement park in Madrid, it is advisable to go from Monday to Thursday, you will enjoy the shows and attractions more and you will not have to wait to be able to ride.
The Madrid amusement park is located in the Casa de Campo, a place with a lot of nature, one of the green lungs of Madrid. In addition, to be able to go to the amusement park you have public transport that leaves you a 5-minute walk from the metro stop. from Batán located on line 10. link in this web site:
https://www.parquedeatracciones.es/prepara-tu-visita/informacion-relevante/como-llegar
In our case, we wanted to spend the day with the child and due to his height he could not access the more risky attractions, therefore we were in the Nickelodeon area, where the little ones can enjoy a lot of activities such as: Jellyfish Patrick, SpongeBob’s house, Paw Patrol roller coaster…etc. I leave you photos and a link so you can see it for yourself.
https://www.parquedeatracciones.es/blog/ampliacion-de-nickelodeon-land
You can also bring your food and drink or buy it inside the park where there are several food stalls, although they are usually quite expensive. I hope you liked it and that you can enjoy it as we did, I leave you the website so you can check rates and schedules. Greetings 
ha ha. Thank you very much for the comment, I hope you have a good day